Lecture 1 and 2 - Intro and What is Biochemistry? Flashcards
Macromolecules
Chemical foundations of cells
Made up of building blocks
Nucleic acids
DNA and RNA
Polymers of nucleotides
Store and transmit information
Proteins
Polymers of amino acids
20 (standard) amino acids that differ by their ‘R’ group (side chain group)
Molecules by which cells perform their function in the whole organism
Carbohydrates/complex polysaccharides
Polymers of monosaccharides aka simple sugars
Have various diverse function sin cells such as being energy molecules, having structural roles, recognition
Lipids
Hydrophobic, structurally heterogenous (non-polymeric) molecules
Have various diverse functions in cells e.g. structural roles in cell membranes, regulatory roles, energy source
Central dogma of biology
DNA to RNA to Protein
DNA replication - transcription - translation
Why is structure of a protein important?
It determines function
Sequence of amino acids determines…
how the protein folds
Primary structure
Amino acid sequence
Secondary structure
Regular sub structures such as beta sheet or alpha helix
Tertiary structure
Three-dimensional structure
Quaternary structure
Complex of protein molecules
Stabilisation of tertiary structure
Non-covalent interactions
- Hydrogen bonds
- Ionic bond
Non-polar/hydrophobic interactions (things like methyl groups interacting with each other)
Covalent interactions
- Disulfide bonds
Disulphide bonds/bridges
Disulfide bonds, covalent linkages between the sulfur-containing side chains of cysteines, are much stronger than the other types of bonds that contribute to tertiary structure.
What happens when amino acid sequence changes?
The structure of the resultant protein is changed, therefore its function is also affected and changed
